Cycle performance of low GWP refrigerant mixtures R-32/1234ze(E) and R-744/32/1234ze(E)

Cycle performance of a vapor compression loop using low GWP refrigerant mixtures are experimentally assessed in this study. The coefficient of performance (COP) of typical heating and cooling mode of air conditioning conditions are measured for R-32/1234ze(E) and R-744/32/1234ze(E). The COP of R-32/1234ze(E)(43/57 mass%) and R-744/32/1234ze(E) (4/43/53 mass%) of GWP = 300 slightly excesses that of the conventional refrigerant R410A. The COP of R-32/1234ze(E)(28/72 mass%) and R-744/32/1234ze(E) (9/29/62 mass%) of GWP = 200 is however lower than that of R410A. The characteristics in COP are explained by the analysis on irreversible loss. The insufficiency of volumetric capacity in the mixtures of GWP = 200 significantly increases the loss related to pressure drop. The less subcooling interfered with the large temperature glide of mixtures cause large throttling loss. The unmatched temperature glide to the temperature change of heat source and/or heat sink fluid increases the irreversible loss in heat exchangers.